Parts of an Experiment

EXPERIMENT n Organized procedure for testing a hypothesis –When designing an experiment there are certain things that you will need to include for it to be valid.

Most experiments will need: n Control Group - “standard of comparison” Closest to actual conditions n Experimental Group - Differs from the control group by one factor or condition (which is called a…)

VARIABLE n The condition that makes the experimental group different from the control group. –You will want your experiment to have only one variable in it for the experiment to be valid.

Example: n Can plants grow without light? –What would be my control group? –What would be my experimental group? –What would my one variable be? There are two types of variables to be familiar with…

Independent Variable n A factor that the experimenter has full control over and changes to see what happens n The “CAUSE”

Dependent Variable n A factor that changes because of what the experimenter does n The “EFFECT”

What about the things that need to be the same in both the control group and the experimental group? These things are called...

CONSTANTS n A factor that does not vary in an experiment –(It is the same in the control group as in the experimental group)